“The Genius of Birds”, a book by Jennifer Ackerman, posits that birds are much more intelligent than we usually assume, rivaling primates and even humans in some forms of intelligence. The book contains research and examples of how birds use their “genius” in unique and technical ways. Fascinating!

Chris Templeton, TM Freeberg and JR Lucas, among others, studied the calls of black-capped chickadees (Poecile atricapillus). In addition to passing along information about their location and food sources, chickadees communicate threat, both the type of predator and the magnitude of its threat.

When a chickadee makes a high-pitched, soft “si-si-si” it indicates that there is a predator, such as a sharp-shinned hawk or shrike, on the wing. A stationary, perched predator elicits the familiar “chick-a-dee-dee” call. The number of “dees” at the end of the call indicates the size of the predator, hence the threat. More “dees” mean a smaller, more dangerous predator while fewer “dees” warn of a larger nearby bird.

Why is a larger bird such as a great-horned owl less dangerous than a small predator, a pygmy owl for example? The smaller predator is more agile and can maneuver more easily amid the tree branches and is thus a greater menace.

Soard and Ritchison studied the alarm calls of the Carolina chickadee (Poecilecarolinensis) and demonstrated the same pattern of using “dees” to indicate the magnitude of the threat. They suggest that other chickadees, including the pictured mountain chickadee, probably communicate danger in the same manner.

This mountain chickadee (Poecile gambeli) was photographed near the Lower Ash Creek Campground (Lassen County CA).